Hello i have a 1997 f150 lariat And its got about 160,000 On it. For a few months now my truck has been maeking this weird clunk sound. i believe its coming from the drive shaft area. It happens when you accel and release the gas. So from a dead stop and you push the gas for a few secs and release it. i hear a moderate clunk sound! I cant figure out what it is. i raplaced my u joints caus ei thought that may be it. but if anyone can help me. PLEASE i dont want something to break off it while im driving. thanks alot!

 

Have you lubricated the slip yoke on the driveshaft? It is a known problem on these trucks, there is even a TSB for it.

 

Yea , you have to clean the tailshaft /spline with brake cleaner or something of that nature and apply Teflon Grease (A thin coat to the spline) - Make sure it's good and clean first + dry before you apply the grease..

That was the "Clunk" TSB if I remeber right..

 

I am having a similar problem on a 2004 F-250 only when 4x4 is engaged. When in 4x4 there is a constant clicking/clunking noise that is more clearly heard when not accelerating (off the gas). It only makes the noise when in 4x4, could this be the front drive shaft spline/ UV joint? Does it just need to be cleaned and greased?
Thanks!

 

Clean and lube the slip yoke. If you chose to take it to the dealer they should charge you 1/2 hour labor for the job. There is a TSB on this that is specific about the type of grease that must be used if you wish to do it yourself. Of course the dealers do this all day long and have the correct grease on hand.

 

I had mine greased by firestone when they did ujoints. Only lasted a week.

Great tip on the brake cleaner. I'll have to do that in the spring on my 97 and grease it up and hopefully it lasts.

 

You may already know it is the drive shaft or related. But, just for discussion when my truck did this it turned out to be the leaf springs sliding against each other and against the hanger/shackle.

I cleaned/greased the spline etc. and it still made the noise so I ended up looking for other parts that move against each other during accel/decel.

Some cleaning/light lube of the leaf assembly made the sound go away. There was also a little plastic leaf shim that had worked its way loose that I had to jimmy back into place and make secure.

 

my truck is a 04 and i notice your all 03 and previous.

mine does it the odd time on accel and braking, but i can always make it do it on a hill, (ride down the hill with my foot off the gas and have the momentum of the truck keeping the engine turning (engine braking), then give it gas and have the engine start pulling the truck and it does a huge clunk.

it has the factory sealed driveshaft on it still. could someone be so kind as to show me in a picture what exactly i am lubricating.

thx.

 

Pull the shaft- You lube where it slides onto the tail shaft @ the transmission.